(295d) Ionic Liquids Assisted Preparation of Cellulose Coated Bacterial Biosorbents

Biosorbents prepared from natural sources have a great potential as low-cost competitive sorbents able to bind ionic species in solution phases. However, their mechanical strength and chemical stability especially under acidic condition should be improved to be used for the practical application. This study aimed at solving these bottlenecks with help of cellulose dissolved in ionic liquids. Waste bacterial biomass generated from an amino acid fermentation industry was used as raw material. The raw biomass was chemically modified and immobilized with chitosan for increasing the binding sites for ionic solutes. To make process applications possible, the chemically modified biosorbents were molded as spherical and fiber shapes. A simple but effective way to coat cellulose on the surface of biosorbents was developed and will be presented. Briefly, the half-dried biosorbents were brought into contact with dissolved cellulose in ionic liquids. Then water was left to release from the inside to the surface of biosorbents, and cellulose surrounding the biosorbents began to precipitate on the surface, making the thin cellulose film. Resulting cellulose-coated biosorbents had enough mechanical strength to be applied in column-type rectors. Furthermore, the developed biosorbents were stable in acidic and chloride-rich solutions. Successful applications of the developed biosorbents for removal and/or recovery of toxic or precious solutes from the aqueous phase will be demonstrated in this presentation.